摘要
为了研究新建隧洞对下穿既有铁路路基的影响,以宝鸡峡引水隧洞下穿陇海铁路线为研究背景,采用数值模拟方法,系统分析地层劣化程度、盾构施工参数、加固措施对铁路路基的沉降规律及盾构管片的力学响应。结果表明:引水隧洞围岩劣化系数降低至0.7时,铁路路基沉降增加约16%,衬砌拉压应力分别增加约4%和9%;随着盾构土舱压力和推力的增加,路基沉降分别减小约79%和4%,衬砌拉应力分别增加约55%和44%;随着注浆压力增加,路基沉降减小约26%;超前注浆圈厚度增大,可控制沉降降低19%,D型施工便梁型号越高,铁路路基的沉降越小,最低降至2.8 mm。在盾构掘进期间应避免盾构机过度扰动地层,采取地层超前注浆的加固圈厚度宜控制在2 m以内或采取D20型施工便梁加固既有铁路线。
In order to analyze the impacts of newly constructed tunnels on the underpass of existing railway embankments,against the backdrop of the Baojixia Diversion Tunnel passing under the Longhai Railway,numerical simulation method was adopted,the settlement law of railway subgrade and the mechanical response of shield segment was systematically analyzed,the law was included with formation deterioration degree,shield construction parameters,reinforcement measures.The results are as follows.The settlement of the railway subgrade was increased by approximately 16%,due to the deterioration coefficient of surrounding rock was reduced to 0.7.The tensile and compressive stresses within the lining was enlarged by 4%and 9%respectively.The increase in shield earth pressure and thrust contributed to the reduction of the subgrade settlement by approximately 79%and 4%,respectively.While the tensile stress in the lining was expanded by about 55%and 44%,respectively.With the increase of grouting pressure,the settlement of the subgrade was reduced by approximately 26%.With the increase of advance grouting ring thickness,the controlled settlement was reduced by 19%.The higher the type of D-type construction beam,the smaller the settlement of the railway roadbed,the lowest dropped to 2.8 mm.To ensure the operational safety of the existing railway line.To ensure the safety of existing railway lines,excessive formation disturbance and power loss of shield machine was avoided during the shield tunneling.The thickness of reinforcement ring for advance grouting was controlled within 2 m,or the existing railway line was reinforced with D20 type construction beams.
作者
赵玮
张静
王瑜
陆丽
朱才辉
ZHAO Wei;ZHANG Jing;WANG Yu;LU Li;ZHU Caihui(Shaanxi Institute of Water Resource&Electric Power Investigation&Design,Xi′an,Shaanxi 710001,China;Institute of Geotechnical Engineering,Xi′an University of Technology,Xi′an,Shaanxi 710048,China)
出处
《水利与建筑工程学报》
2024年第6期1-8,共8页
Journal of Water Resources and Architectural Engineering
基金
国家自然科学基金项目(52279110)。
关键词
引水隧洞
盾构施工
铁路线
控制措施
沉降
diversion tunnel
shield construction
railway lines
control measures
sedimentation
